Hot-air furnace.



No. 757,521. 7 PATENTED APR. 19,1904.

E. A. TUTTLB, 'nac'n.

A. o. a a. B. TUTTLE, nxnom'ons. HOT AIR FURNACE.

APPLICATION nnnn uomas. 1900. Bmrnwnn JAN. 13; 1904. 7

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zwmvsssss; g2 mvguron' m I (:6 ad? $1 5 r ATTORNEY UNITED STATES l atented April-19, 1904.

PATENT OFFICE;

EDWARD A. TUTTLE, OF NEW YORK, N. Y-.; ARTHUR C. TUTTLE AND HERBERT B. TUTTLE EXECUTORS OF SAID EDWARD A. TUTTLE,

DECEASED.

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Fatent N0. 7 57,521., dated April 19, 1904.

Application fil d November 28, 1900. Renewed Tanuary 13,1904. Serial No. 188,924 (No model.)

To aZZ whom it may concern/.-

.Be it known that I, EDWARD A. TUTTLE, a citizen of the United States of America, and a resident of New York city, county and State of New York, have invented certain new anduseful Improvements in Hot-Air Furnaces, of which the following is a specification.

My invention relates to hot-air heating-furnaces; and the object is to provide for more effectively charging the air with aqueous vapor and for more effectively and economically heating the air through the instrumentality of the aqueous vapor with which it is charged, as herein after.described,reference being made to the accompanying drawings, in which Figure 1 represents a central sectional elevationof a furnace adapted for the application of my invention. Fig. 2 represents a transverse vertical section on line 2 2 of Fig. 1. Fig. 3 represents a horizontal section on line 3 3 of Fig. 1.

My invention is applicable to furnaces of different constructions,and the particular construction herein represented is only taken as one example of suitable construction for the application; The construction will not therefore be definitely described, it being only necessary to give a general understandingofthe parts not claimed and to particularly point out what is claimed. a

The metallic fire-box 0;, having an inclined self-feeding magazine Z) and grate o, is placed in a brick inclosure d, in which it is supported on abutments e, and in the front wall f,

where the ash-port g and the magazine 6 project through said wall, with intervening space it for causing e fiective contact of the air for transmitting the heat with the plates of the fire-box for being heated. The air enters the space lahereinafter called the secondary airsiderable extent before entering the hot spaces of the secondary air-chamber next to the firebox. The air in primary chamber Z is further heated by flues 0, located therein and receiving the hot products from the fire-box through pipes 19, communicating with the fire-box at r g and passing through walls 0?. The flues 0 discharge through branch pipes 8 into smokeh pipe t, which connects with the chimney, as usual, for discharge into the air, said pipe 25 being located in the cold-air inlet mfor giving up as much as possible of the heat of the waste products before escaping. The fines are made wide and shallow, as represented in Fig. 2, for affording large area of surface exposure proportionately to the volume capacity for economy in heating the air by contact, which is known to be the essential way, as air does not absorb radiant heat. In the primary chamber Z of sucha furnace or any other having a primary chamber of similar character I arrange evaporating-pans a under the flues 0, so as to intercept the air flowing in the direction of the passages i for absorbing vapor from water therein,said pans being preferably located in the two opposite sides of the chamber h, with a baffle-plate w in the back part of said chamber to prevent escape of the air thereat without contact with the water, or another pan may be employed instead of the baffleplate and the pans u terminate at o a little short of the front wall f to provide passages m for the escape of the air after traversing the evaporating-pans to the passages i for entering the secondary and more effective heating-chamber.

The principle of my invention is based on these facts: First, dry air does not intercept radiant heat-rays and is only heated by convection; second, the aqueous vapor of saturated or partly-saturated air absorbs radiant heat and by contact of the intimately -miXed particles of vapor and air largely increases the heat ofthe air,whereby,together with the heat of contact with the fire-box, the air is more rapidly, thoroughly, and economically heated; third,- saturated orpartly-saturated and heated air is more active and circulates more forcibly because of the greater heat required from the two sources; fourth, air at 7 0 Fahrenheit absorbs the proper quantity of vapor for healthful use in living-rooms. At higher temperature it absorbs morevapor than it will retain on being reduced to the required temperature in the rooms and deposits the surplus by condensation,- the evil effects of which are well known. With these facts in view the essential feature of my invention consists of a furnace provided with a primary heatingchamber containing vapor-generating means into which the air is supplied and adapted for heating the same from, say, about 12 to 30 Fahrenheit to about 7 0 Fahrenheit while absorbing the vapor, and asecondary chamber of much higher heat, but excluding the air from any source of moisture after entering it, and adapted for heating the air previously charged with vapor as high as may be desirable for carrying the requisite amount of heat into the rooms.

Further illustration of the principle and advantages of my invention may be stated as follows: One hundred cubic feet of saturated air at 7 0 Fahrenheit contains .114 pound of vapor and 7.311 pounds of air. Therefore nine hundred cubic feet of dry air at 7 0 Fahrenheit absorbs about one pound of vapor in comingto the point of saturation. The ordinarysized dwelling-say forty by thirty five by thirty-contains about forty thousand cubic feet of air. To maintain this amount of air at 7 0 during the winter outside temperature ranging from 12 to 32 will require from four thousand to six thousand cubic feet-per hour of newly-heated fresh air to be introduced to displace that quantity of present air, requiring about four pounds water evaporated per hour less by that with which the air is previously permeatedsay one-fourth. Since air will take up only .114 pound of vapor at 70 per one hundred cubic feet, a surplus area of evaporating-surface can do no harm; but not less than six square feet should be provided in the passage-ways underneath the smoke.- pipe chambers in the above case. The moisture having been thus evenly and thoroughly mixed with air at about 70 Fahrenheit, the radiant heat from the secondary or inner chamber being much hotter. is immensely more effective in heating such thoroughly-saturated air, thereby many times increasing the force and temperature of the current of hot air delivered through the registers into the rooms above, and if the air so delivered be of a temperature so high as-150 or even 180 it is easily regulated so as to mix with and keep the air at its proper warmth in the room at 68 or 70. The immensely-increased power of radiant heat to impart its heat to a current of air which is already saturated with moisture at the temperature it is needed for dwellings (7 0) enables the making a much hotter, quicker,

and more effective current against counter adverse currents from outside 'by windows and doors, and when cooled to the proper temperature in the rooms the heat of condensation helps to maintain that temperature. The colder the air outside the quicker is the current. Therefore having adjusted the supply of outside air to the lower temperatures of the locality the diminished currents for the higher temperatures will regulate the amount of fresh air needed for warming the rooms above.

7 By placing the evaporating-pan in the primary chamber, where the temperatureis about and not above Fahrenheit, and providing there suflicient evaporating-surface to saturate the air at that temperature the following beneficial effects are attained: First, a natural and healthful amount of moisture is supplied to the air of living-rooms; second, the heating power of the fire-box is many times increased, the evenly-distributed supply of attenuated vapor absorbing the radi-' ant heat and indirectly heating the air with which it is in contact; third, the air in the ascending current is not displaced, as is done by placing the evaporating-pan in contact, or nearly so, with the fire-pot, where evaporation takes place in a temperature of about 212 Fahrenheit; fourth, counter-currents and retardation of the upward current is avoided, as no condensation takes place until the warm current reaches the rooms, as is the case where the evaporation takes place at 212; fifth, the prevention of the chilly feeling that is often experienced in heated rooms produced by the too-rapid absorption of the insensible perspiration of the body because of the dryness of the air.

What I claim as my invention is The combination in a hot-air furnace, of the primary chamber receiving the air to be heated, and adapted for moderately heating the air, the secondary air-heating chamber inclosed in the primary chamber, the fire-box contained in said secondary heater, and adapted for more highly heating the air, a series of passages for the air from the primary chamber to the secondary chamber located along the bottom of the wall separating the two chambers, an evaporating-pan located in the primary chamber above said passages and constituting a baffle devicecausing the air to traverse said chamber laterally from the coldair inlet to the passage into thevspace below the pan, and v along said space from the inlet into it to the series of passages therefrom into the secondary chamber.

Signed at New York city this 28th day of September, 1900.

EDWARD A. TUTTLE.

Witnesses:

A. P. THAYER, C. SEDGWICK. 

